The present invention relates to a method for the display of time-variable physical parameters as well as to an apparatus making it possible to carry out this method.
It more particularly applies to the display of the graph or graphs representing the development of relative values of physical parameters. The invention also applies to the display of the graph representing the relative development of physical parameters with respect to time. In both the aforementioned applications, the values of physical parameters are acquired as a function of time. This method apparatus can more particularly be used in checking the operation of any installation in which the physical parameters are measured periodically by choosing predetermined sampling frequencies. These measurements make it possible to follow the development of the operation of this installation over a period of time and optionally to intervene in the case of an incident in said operation. For example, this is the case in nuclear reactors, where it is necessary to detect any axial unbalance of the reactor power, so that it can be effectively cured. This unbalance is detected by following, during operation, the development of the reactor power value as a function of the high and low flux values generated by the fuel. Constantly following this development makes it possible to control the reactor in such a way that it operates at its maximum power. It also makes it possible to carry out rapid power variations, such as the daily load variation. This control consists of modifying the level of the control rods in the reactor vessel or the boric acid concentration.
At present, no system or process for the display of variable parameters in time are known which make it possible to display the development of the values of one of these parameters compared with the other and optionally the development of the values of one of these parameters compared with the other as a function of time, the values of these parameters being supplied initially and separately, as a function of time. In addition, no process or system are known making it possible to display these developments in accordance with variable scales and in accordance with variable periodic sampling of these parameters which develop with respect to one another and optionally with respect to time.
The known devices include plotting tables or multicurve display systems, which only make it possible to simultaneously represent the variations of the values of two physical parameters relative to time. These processes and systems do not make it possible to also represent variations of one of these parameters relative to the other and optionally relative to time. In addition, these known devices only make it possible with very considerable difficulty to vary the sampling or acquisition frequency of these parameters, to vary the display scale of the graph representing their relative development and to vary the selection frequency of the relative values of these parameters, in order to display the graph representing this development over a period of varying length. These systems do not make it possible to accurately determine the paths followed during the variations of parameters producing loops.